1. Field of the Invention
The invention relates to an improved structure of transformer's lead frame, and more particularly, to an improved structure of transformer's lead frame capable of providing temporary positioning of the coil's drawing heads to prevent the iron core' assembling work from being interfered by the occupied position of the coil's drawing heads.
2. Description of the Prior Art
FIG. 1 is an isometric exploded view of the structure of the transformer or inductance of the prior art while FIG. 2 is an isometric view of the assembled outward appearance of the structure of the transformer or inductance of the prior art. As shown in FIG. 1 and FIG. 2, the transformer or conductor structure of the prior art mainly includes a lead frame (8), iron core (9, and coil (821) where the lead frame (8) has a central hole (81) furnished at the center thereof. A bobbin (82) furnished around the outer circumference of the central hole (81) for the coil (821) (the coil 821 includes a primary winding, a secondary winding, and, according to the requirement, a control winding) to be wound. A pair of extension parts (83), (831) are furnished near the central hole and extended toward both side therefrom. These extension parts (83), (831) are connected to the mid-section of two wire connecting seats (84), (841). Two wire connecting posts (85), (851) that pull out drawing heads from the coil (821) are furnished at the extension parts (83), (831). The iron core (9) has a main core part (91) furnished at the center of the inner side surface thereof. The main core part (91) has a containing circumferential trench (93) furnished at the periphery thereof, and at the periphery of the containing circumferential trench (93) has two oppositely configured side openings (94), (941) that are outwardly communicative. Two oppositely configured side parts (92) are naturally formed for the rest of the part of the outer circumference of the containing circumferential trench (93). When it comes to assembling, the two main core parts (91) will contact each other after the main core parts (91) of the two iron cores (9) are stretched through the central hole (81) of the lead frame (8). In the mean time, the containing circumferential trench (93) will contain the lead frame (8) and the two extension parts (83), (831) will stretch outward through the side openings (94), (941) making the wire connecting seats (84), (841) and the wire connecting posts (85), (851) keep at the position outside the iron core (9). In this way, the circumference of the coil (821) in the bobbin (82) is capable of forming a magnetic loop.
In accordance with the machining process in production, conductive wire or enamel covered wire is wound around the bobbin (82) of the lead frame (8) (to form coil 821), then the lead frame (8) is combined between the two iron cores (3). However, since there is no furnished mechanism of temporary fixing for the drawing heads of the coil (821), the current method is to have the drawing heads directly braze and connect to the wire connecting posts (85), (851) after the winding work of the coil is completed, i.e. the drawing heads are directly braze to the wire connecting posts (85), (851), then the lead frame (8) is combined to the two iron core (9) or the drawing heads are temporary fixed by other methods, afterward, the drawing heads are brazed to the wire connecting posts (85), (851).
Nevertheless, in actual operation, in order to diminish magnetic leakage, generally, the width of the side openings (94), (941) of the iron core (9) is only allowed to be passed through the extension parts (83), (831), and the width of the wire connecting seats (84), (841) of the lead frame is much larger than the width of the extension parts (83), (831). As a result, after the winding work of the coil (821) is completed, the extension direction and position are different following the different positions of the wire connecting posts (85), (851) of the corresponding connection; as the drawing heads A and B shown in FIG. 1, the drawing head B is connected to the wire connecting posts (85) that is relatively closer to the center part, its extended position will keep within the extension part (83), thereby it will not interfere the assembling work of the following iron core (9). However, the drawing head A is connected to the wire connecting post (85) that is relatively closed to the outer part, thereby, if in negligence, the extension position is quite possible to be directly moved to the outside of the extension part (83). At this moment, it is necessary to remove that will directly affect the overall assembling efficiency, otherwise, if in negligence, it will result in defective product.
Therefore, the structure of the transformer's lead frame is still needed to be improved in practical application.